Stepping Around a Painted Hole

The first anamorphic picture I studied in art class was Hans Holbein’s The Ambassadors, painted in 1533 and now in the National Gallery in London. Across the bottom of the painting there’s a long, smeared gray shape. From the front, it’s nothing. But stand off to the right and look along the canvas, and it pulls together into a human skull.

That’s the whole trick of anamorphosis. The artist stretches an image so it only looks right from one spot. Modern 3D street artists use the same idea on pavement. They paint a stretched pit or cliff edge on the ground, and from the right spot the street seems to drop away in front of you.

Prank videos online show people jumping back, freezing, or stumbling at these paintings, and I can’t tell how many of those clips are staged, or even real. The documented cases are calmer. In 2008, the German artist Edgar Müller painted The Crevasse, an icy chasm covering 250 square meters of pavement in Dún Laoghaire, Ireland. A Gulf News profile noted that people at first “might step around or over” his paintings, before jumping in to pose for photos. Even that small step around raises a real question. These people know they’re on a sidewalk. Their feet never leave flat ground. So why does a picture reach their legs before their knowledge does?

The psychologist James J. Gibson gives part of the answer. In The Ecological Approach to Visual Perception (1979), he argued that we don’t mainly see the world as pictures to think about. We see what it lets us do, which he called affordances. Solid ground affords walking. An edge affords falling. Seeing a drop isn’t a fact you think about first and act on later. It’s already information for your feet.

His wife, the psychologist Eleanor Gibson, tested something close to this with Richard Walk. In their 1960 “visual cliff” study, babies crawled on a sheet of thick glass. Under one half, a checkered pattern sat right below the glass. Under the other half, the same pattern was about four feet down. The glass was safe everywhere. When their mothers called from the deep side, only three of the 27 babies who had crawled off the center board went across. Some patted the glass with their hands and still wouldn’t cross. Their hands said solid. Their eyes said drop. The eyes won.

That’s the same contest as on the sidewalk, with touch playing the part of “it’s just paint.”

A second experiment shows that vision doesn’t only warn us. It holds us up. In 1974, David Lee and Eric Aronson put toddlers who had just learned to stand inside a small room whose walls and ceiling could slide while the floor stayed still. When the walls moved, the children swayed, staggered, and sometimes fell. Their eyes told them they were tipping, so their bodies corrected for a fall that wasn’t happening. Balance runs on the inner ear and the muscles, but also on what we see, and it doesn’t wait for anyone to think it over.

So the step around makes sense. The pedestrian’s balance system reads the painted edge like any edge and reacts right away. “It’s just paint” is a sentence, and sentences are slower.

But as an art student, I notice something the prank videos leave out. Anamorphic art only works from one spot. Take a step and the perspective falls apart. The pit stretches back into a flat, strange shape, which is why street artists often mark the exact place to stand for photos. A real hole doesn’t do that. As you walk toward a real hole, its edges shift the way a drop should. Gibson cared about this. He thought normal seeing happens while we move, not from one frozen point.

That means the painting is fighting the very thing Gibson said vision is for. A person walking past gets the full illusion for a step or two, and then their own motion breaks it. The step around doesn’t show that the painting fools you completely. It shows how quickly your body acts in the one moment it does.

Most paintings are made for the part of vision that looks. A pit painted on a sidewalk is made for the part that keeps you standing, and it only has one step to work.

Editor’s note: you can try this yourself. Find the Spot puts you on the marked spot in front of a painted pit, lets you walk away from it and compare it with a real hole, and then shows what the artist actually painted on the ground.